Typically, a steering assembly of a vehicle includes a steering column extending between a steering mechanism, for example, a steering wheel, and a torque distribution mechanism. The steering column is designed to translate rotation of the steering wheel by a vehicle operator to the torque distribution mechanism which correspondingly positions the wheels of the vehicle in accordance with the position of the steering wheel, thus steering the vehicle.
It is desired that the steering column be of a sufficient compressive, shear, and torsional strength to endure the above described usage. The steering column designed as such can have a substantial mass and thus must be properly supported within the vehicle for effective functioning of the vehicle steering assembly.
Accordingly, the steering column is supported by attachment to a cross-car structural beam located within the vehicle. The load resulting from the weight of the steering column and other loads encountered during vehicle usage are distributed through the cross-car structural beam to side walls of the vehicle and/or to other parts of the vehicle where the cross-car structural beam is mounted thereto. The weight of the steering column is thereby conveyed, through the side walls and/or other vehicle parts, to a steel frame of the vehicle. Other parts of the vehicle which lend to the structural support system include, for example, a vehicle body, a front-of-dash, etc.
The cross-car structural beam is generally a load-bearing member that is also used to support an instrument panel assembly and a heating ventilation and air conditioning (HVAC) structural duct system, both located about the beam. The structural beam further serves as a reaction surface for occupant protection devices such as air bags or knee bolsters.
The steering column is typically attached to the cross-car structural beam directly or by a steering column support structure. The steering column support structure is composed of a metal or a composite and is attached at a first end to the cross-car structural beam and at a second end to the steering column.
The steering column support structure must support the load of the steering column and other loads associated with vehicle usage and effectively distribute the loads to the cross-car structural beam for distribution to the side walls of the vehicle.
Typically, the steering column structural support is mechanically attached at the first end to a load bearing area of the cross-car structural beam. The load bearing area is generally a portion of the cross-car structural beam and may be located, more specifically, at an underside of the beam. The steering column structural support is attached to the load bearing area by one or more threaded bolts and secured with fasteners such as nuts.
Lightweight air duct assemblies are composed of a molded plastic or a molded plastic composite and are mounted to the rigid cross-car structural beam. A metal-to-plastic interface between the nut/bolt arrangement and the air duct tends to degrade the plastic of the air duct. Hence, the overall attachment of the steering column and the cross-car structural beam is degraded. Thus, the use of extra parts, such as washers and the like, must be employed to preserve the plastic of the structural air duct.
The attachment of the steering column structural support and the cross-car structural beam using the nut/bolt arrangement must be performed manually and requires the handling of several parts and tools, thus valuable labor time is consumed and extra expense incurred.
Accordingly, it is desirable to have a structural attachment system for attaching, inter alia, a steering column to a cross-car structural beam that is light weight, simple to manufacture and assemble, provides an effective and efficient means to provide HVAC ducting and allow attachment of other components without the addition of separate brackets and additional hardware. Thus, a structural attachment system having less parts and assembly, more strength, and increased packaging space is desirable.